Polyvinyl chloride resins are known as substrates having poor adherend properties, and it is difficult to thermally adhere these polyvinyl chloride resins to different materials such as other thermoplastic resins and metals.
It has been conventionally known that some of thermoplastic resins show thermal adhesion properties to polyvinyl chloride. However, most of these resins are insufficient in adhesion to other thermoplastic resins or metals, and they cannot withstand uses as adhesives depending on cases.
By the way, a graft modified product of an ethylene/vinyl acetate/carbon monoxide terpolymer (modified terpolymer) proposed by the present applicant in Japanese Patent Laid-Open Publication No. 60(1985)-158282 exhibits good adhesion to various adherends including polyvinyl chloride, and it can be used as an excellent adhesive. However, this adhesive has been desired to be much more improved in the practical use. That is, this adhesive (graft modified product) is easily colored in the preparation thereof and is hardly obtained as a colorless and transparent one, and hence there is yet room for improvement in the case of using this adhesive as an adhesive for adhering transparent substrates together. Further, it is difficult to use this adhesive in such a case that the adhesive is extruded together with high-melting materials such as polyamide and polyester, because the adhesive is not always sufficient in heat stability at high temperatures.
In the light of the foregoing, the present inventors have earnestly studied to pursue adherent resins having higher general-purpose properties, for example, capable of being used as the adhesion for polyvinyl chloride resin and other material, and as a result, they have found a novel modified terpolymer (graft modified product) which is by no means inferior to the aforementioned modified terpolymer in the adhesion properties and is excellent in other properties such as hue and heat stability. However, it has been also found that there is yet room for further improvement in this novel modified terpolymer in the heat resistant adhesive properties or adhesion to polyester, and therefore this adhesive is eagerly desired to be much more improved in those properties in order to increase general-purpose properties.